In International Application No. PCT/US02/09543 entitled “Wireless System for Measuring Distension in Flexible Tubes” to Kain (“Kain I”), which is hereby incorporated by reference, methods for measuring blood parameters in living beings are described. As is disclosed in Kain I, it is known in the prior art to measure blood pressure by the implantation of a miniaturized sensor via catheterization. As catheterization in humans ideally requires that the overall diameter of an implanted sensor be 2 millimeters (mm) or less, self-powered sensors that contain internal batteries are not practical at the present time. Hence, other means for supplying energy to the sensor such as energy scavenging by the sensor or external power means are required in order for the sensor to function and meet the size constraints required by the catheterization procedure.
Kain I discloses a pressure sensor including a resonant circuit externally powered and interrogated by radio frequency identification (RFID) techniques to provide a response signal that can be correlated to an implied blood pressure within a blood vessel. However, such response signals may be deleteriously affected by interrogation signals generating signal artifacts including reflections from a variety of sources and other unwanted signal responses.